This topic describes how to tune the HP-UX operating system
to optimize the performance of your WebSphere® Application
Server. Because the HP-UX operating system is not a WebSphere Application
Server product, be aware that it can change and results vary
Before you begin
On the HP-UX operating system, WebSphere Application
Server runs on the Java virtual machine (JVM), which
is based on the technology of Sun HotSpot JVM. Properly tuning this
JVM significantly affects WebSphere Application Server
performance by fully utilizing its performance optimizing characteristics.
See the setting up the JVM on the HP-UX system information. It is
also important to change some parameters that are specific to the
HP-UX operating system to prevent WebSphere Application
Server from being deprived of resources.
About this task
When you have a performance concern, check the operating
system settings to determine if they are appropriate for your application.
Procedure
- Configure the following settings and variables according
to your tuning needs:
- Tuning the HP operating system with the DB2® type
2 JDBC driver
When using the type 2 Java Database
Connectivity (JDBC) driver on the HP operating system with DB2,
you can increase the performance of WebSphere Application
Server by preallocating the DB2 trace segment. Perform the
following steps:
- Before starting application server, switch to the user that is
associated with the DB2 instance.
- Run the db2trc alloc command.
- Start application server.
Usage note: Use the type 4 driver for best performance
and compatibility.
Another issue with the type 2 JDBC driver
on the HP operating system is code page conversion. Creating the database
using the UTF-8 code set avoids this problem and significantly increases
performance. See the database documentation for instructions on creating
databases with a specific code set. Read the DB2 tuning
parameters information.
- The HP performance tuning parameters
Modify HP-UX 11i
settings to significantly improve WebSphere Application
Server performance. For additional information about the HP performance
tuning parameters, see the performance: resources for learning information.
- Java virtual machine (JVM) virtual page size
- Description: Sets the JVM instruction and data page sizes
to 64 MB to improve performance.
- How to view or set: Use the WASHOME/java/bin/SYSTEM_ARCH_PATH/java command.
The command output provides the current operating system characteristics
of the process executable.
- Default value: 4 MB, if not assigned
- Recommended value: 64 MB
- HP-UX 11i TCP_CONN_REQUEST_MAX
- Description: Specifies the maximum number of connection
requests that the operating system can queue when the server does
not have available threads. When high connection rates occur, a large
backlog of TCP/IP connection requests builds up and client connections
are dropped. Adjust this setting when clients start to time out after
waiting to connect. Verify this situation by issuing the netstat
-p tcp command. Look for the following value: connect requests
dropped due to full queue
- How to view or set: Set this parameter by using the ndd
-set /dev/tcp tcp_conn_request_max 8192 command.
- Default value: 4096
- Recommended value: In most cases the default is sufficient.
Consider adjusting this value to 8192, if the default proves
inadequate.
- HP-UX 11i kernel parameter recommendations
Refer to the
table of kernel parameters shown in the "Preparing HP-UX systems for
installation" topic in the information center.
- TCP_KEEPALIVE_INTERVAL
- TCP_KEEPALIVES_KILL
- Keeping current with the operating system and Java patches is one of the most important things
you can do to optimize the performance of a server. For the latest Java patches, visit the following website:
HP-UX Patch Information
Also, for the
latest operating system quality pack, visit the following website:
Support
Plus: Quality Pack Bundles
Results
This tuning procedure improves performance of WebSphere Application
Server on the HP-UX operating system.
What to do next
After tuning your operating system for performance, consult
the other tuning topics for various tuning tips.